1. Field of the Invention
The present invention relates to a backlight assembly. More particularly, the present invention relates to a backlight assembly and a liquid crystal display having the same, which may prevent defects caused by foreign materials.
2. Discussion of the Related Art
Typically, liquid crystal displays (LCDs) show a tendency that their application fields are gradually increased due to the characteristics of light weight, thin thickness, low-power-consumption driving, and so on. Owing to this tendency, the LCDs are applied to office automation equipment, audio/video equipment, and so on. Meanwhile, the LCDs adjust an amount of transmitted light on the basis of image signals applied to a plurality of control switches arranged in a matrix pattern, thereby displaying a desired image on a screen.
The LCDs require a backlight assembly, because they are not spontaneous light-emitting displays. The backlight assembly is divided into a direct type and an edge type according to the position of a light source. The edge-type backlight assembly comprises a light source disposed at the edge of a flat panel, and a light guide plate guiding light from the light source to the front of a liquid crystal panel.
Meanwhile, the direct-type backlight assembly has a plurality of light sources disposed at the rear of a liquid crystal panel. The light sources directly irradiate light throughout the rear of the liquid crystal panel. The direct-type backlight assembly having the light sources can further increase brightness and a light emitting area, compared to the edge-type backlight assembly. The direct-type backlight assembly includes optical sheets that diffuse and collect the light from the light sources. These optical sheets are supported by supporter sides.
An LCD having this direct-type backlight assembly is constructed as in FIGS. 1 and 2. FIG. 1 is an exploded perspective view illustrating a related direct-type LCD, and FIG. 2 is a detailed view illustrating the state in which optical sheets are placed on the bottom cover in part A of FIG. 1.
As illustrated in FIGS. 1 and 2, the related LCD includes a liquid crystal panel 10 displaying an image, and a backlight assembly 20 supplying light.
The backlight assembly 20 includes a plurality of light sources 60 that emit light, a reflector 70 that is disposed at the rear of the light sources 60 and reflects the light, and optical sheets 30 disposed at the front of the light sources 60 and diffusing and collecting the light.
The backlight assembly 20 further includes first and second supporter sides 50A and 50B that are disposed on opposite sides of the light sources 60 and support opposite sides of the optical sheets 30, and a bottom cover 80 that is disposed at the rear of the reflector 70. The first and second supporter sides 50A and 50B are made of a molding, protect opposite ends of the light sources 60, and support the optical sheets 30.
The first and second supporter sides 50A and 50B are provided thereon with first and second stoppers 51A and 51B, which prevent the optical sheets 30 from moving in the direction of line X-X′. Meanwhile, each optical sheet 30 is provided with first and second guide recesses 31A and 31B at the positions corresponding to the first and second stoppers 51A and 51B.
The bottom cover 80 is provided, at opposite edges thereof, with third and fourth stoppers 81A and 81B, which protrude to prevent the optical sheets 30 from moving in the direction of line Y-Y′. The bottom cover 80 is made of metal material, which can increase durability of the LCD.
Although this related LCD having the direct-type backlight assembly includes the first and second stoppers 51A and 51B of the first and second supporter sides 50A and 50B which guide the optical sheets 30 as well as the third and fourth stoppers 81A and 81B of the opposite edges of the bottom cover 80, foreign materials are generated by the friction when the third and fourth stoppers 81A and 81B integrated with the bottom cover 80 made of metal material are brought into contact with the opposite sides of the optical sheets 30.
The foreign materials enter into the backlight assembly 20 to be deposited on the light sources 60. The foreign materials deposited on the light sources 60 interrupt some of the light emitted from the light sources 60, so that black noise corresponding to a shape of each foreign material shows on a displayed image. For this reason, the LCD having the direct-type backlight assembly does inevitably deteriorate a quality of image.